Power saws are a type of cutting tool, which are useful for quickly and easily cutting material, such as construction lumber and other building products. A common type of power saw is a portable circular saw, which includes a drivetrain having an electric motor and an arbor assembly configured to be rotated by the electric motor. A circular saw blade is coupled to the arbor assembly for rotation with the arbor assembly. Typically, the saw blade extends through a footplate of the circular saw to position the saw blade for contact with a workpiece. A user prepares for cutting the workpiece with the circular saw by resting the footplate on the workpiece and aligning the saw blade with a desired cut path. Then the user energizes the electric motor and manually guides the rotating circular saw blade in the direction of the cut path, often following a marked line on the workpiece.
The drivetrain of some circular saws includes a geared transmission assembly arranged between the electric motor and the arbor assembly. Geared transmission assemblies are useful for, among other things, changing the rate at which the saw blade is rotated relative to the rate of rotation of the electric motor. Furthermore, some types of geared transmission assemblies are capable of transmitting high levels of torque for cutting thick and/or hard workpieces.
In some instances a geared transmission mission assembly may generate an undesirable level of heat within the housing (i.e a gearbox) of the power saw. Thus, it is desirable to provide a geared drivetrain for circular saw that effectively transfers torque from the electric motor to the arbor assembly and the circular saw blade without generating an undesirable level of heat.